Step 1: The Light
I apologize for not having a photo of the battery connections, but four year olds don't have much patience to wait for photos once the project starts. We took a battery, wired it to a switch that I took off of a broken light, and used it to turn on and off a small section of LED tape light that can be cut every few inches. Using an old mint tin, we cut a hole in the one end of the tin for the switch to fit in, one on the side (facing the cooler) for the LED wire to come out of, and then closed up the end. We put the switch in the end that didn't open so that we could use the door on the tin to access the battery when it needed changing. I simply connected the switch leads in line on the batteries positive wire and on to the positive feed of the LED strip, then tied together the negative from both the battery and the LED strip. I am using a 9v battery, but by leaving the tins door accessible, any battery configuration that will both run the 3 small LED's and fit in the tin can be used in the future.
Step 2: The Inside
Step 3: That's It!
This is the first instructable my daughter and I have put together. I asked her to think of a project we could do to help us around the house, and this is what she came up with. I look forward to more instructables with my kids as they grow, learn, and get turned on to this awesome community. This little instructable will seem elementary to most, but it sparked my daughters creativity and solved a basic problem for mom and dad - win win.